I have two sets of single ended output transformers with high primary impedances.

One set has a primary impedanced of 13K into 8 Ohms and the other set has a primary impedance of 17.9k into 8 Ohms. These were taken from old reel to reels in which they were driving 4 ohms speakers.

I saw a web site were a guy combined two high impedance output transformers (in series) to get a lower primary. I tried this, combining one of the 13K with one of the 17.9K in series and got a primary of 3362 ohms. Is this ok to do? I should mention that the 13K ohm output transformer is about half the size of the 17.9K ohm output transformer and I wonder if connecting them like this (one big with one small) will put a lot of strain on the smaller transformer? If its ok to do this it would save me from having to buy new output transformer (which would be really great).

The reason your are light on replies is because this needs some analysis to answer your question and you havent supplied all the data needed.

Note that in the article the transformer primaries are connected in parallel and the secondaries are connected in series. Is this how you have wired the two trannies?

The two secondaries will contribute different voltages (not equal) to the speaker. What load gets reflected to the two primaries will be different as well. What Speaker load are you connecting to the series connected secondaries?

If you answer the above, I or someone else may be able to answer the question.

With those 2 i'd look at using the big one as a parafeed for the little one, Use an EL84 with low inpedance speakers (or perhaps an EL95 if you need to use higher impedance speakers). If they were the same you'd have more options.

Thanks to Planet 10 and gingertube for your replies. It seemed like too simple a solution to my problem...and it was. I'm trying to build with what I have. I'll start looking into parafeed and check out the EL95 tube. I'm learning a lot lately. Thanks.